The Animal Models Core will be established for four purposes: (1) to ensure the efficient planning, purchase and utilization of experimental animals including rabbits and mice (transgenic and immunocompromised mice), (2) to provide the necessary facilities and faculty and staff expertise to support four of the five research projects, (3) to provide expertise in mouse and rabbit pathology with up-to-date proficiency in hematopoietic and cancer pathobiology, and (4) to develop new xenografts of human ATL in Nod/SCID mice. Pathology support will be provided by veterinary anatomic and clinical pathologists that are diplomates of the American College of Veterinary Pathologists. Expertise in animal models of iymphoma, leukemogenesis, and bone pathology witi enable appropriate interpretation and evaluation of the mouse and rabbit models in the research projects and comparison to human lymphoma and leukemia. The quality of the research will be improved because personnel (such as a board-certified veterinary pathologist, veterinary pathology resident, and experienced histotechnoiogist) that are well trained in animal experimentation and tissue processing will work with the project leaders to conduct the investigations. A DVM postdoctoral trainee (resident) in experimental pathology will perform all animal necropsies (autopsies), cutting and processing of tissues, and evaluation of histopathology under the supervision of a faculty pathologist. This will provide a high quality, reliable, and consistent service for the research projects. Other services that will be available to investigators include animal clinical pathology, including a full-service hematology and clinical chemistry laboratory in the Veterinary Medical Teaching Hospital that can appropriately analyze samples from all species including mice and rabbits. Faculty consultants for the Animal Models Core will be available from the Transgenic Animal Service in the Department of Veterinary Biosciences. Facilities will include three necropsy rooms (including one devoted to small animal experimental pathology), tissue processing facilities, histology laboratory with four full-time technicians (one devoted to the Core) and an automated Dako immunostainer, microscopy facilities including a 10-headed microscope with video output for conferences, digital gross and microscopic photography, histomorphometry equipment including a fluorescent microscope and Bioquant Nova analysis software, and small animal surgery facilities in the College of Veterinary Medicine. These faculty, staff, and services will provide a unique resource to the research projects and significantly enhance the quality and validity of the research data.